280664221 has 2 divisors, whose sum is σ = 280664222. Its totient is φ = 280664220.

The previous prime is 280664191. The next prime is 280664261. The reversal of 280664221 is 122466082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 246019225 + 34644996 = 15685^2 + 5886^2 .

It is a cyclic number.

It is not a de Polignac number, because 280664221 - 2⁷ = 280664093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280664261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140332110 + 140332111.

It is an arithmetic number, because the mean of its divisors is an integer number (140332111).

Almost surely, 2^280664221 is an apocalyptic number.

It is an amenable number.

280664221 is a deficient number, since it is larger than the sum of its proper divisors (1).

280664221 is an equidigital number, since it uses as much as digits as its factorization.

280664221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 280664221 is about 16753.0361725867. The cubic root of 280664221 is about 654.7301656445.

The spelling of 280664221 in words is "two hundred eighty million, six hundred sixty-four thousand, two hundred twenty-one".